%0 Journal Article %A I. A. Kipriyanov %T Self-adjoint extensions of certain singular partial differential operators %J Doklady Akademii Nauk %D 1967 %P 1236-1239 %V 176 %N 6 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1967_176_6_a6/ %G ru %F DAN_1967_176_6_a6